This invention relates, in general, to the manufacture of semiconductor devices, and more particularly, to a method of fabricating high performance bipolar and MOS devices with improved density and performance.
The fabrication of bipolar integrated circuits has gone to silicide technology, planarized metal interconnects and sidewall spacers in order to improve the device characteristics of bipolar integrated circuits. These methods have improved packing density, performance and yield, among other things. Any further improvements which simplify the process and improve device characteristics will be desirable.
It is also desirable to fabricate bipolar devices and MOS devices on a single chip for making high speed SRAMS, microprocessors, ASIC devices and analog/digital integrated devices. Two of the problems faced here are: (1) typically the performance of one of the devices is compromised for the other, and (2) the incompatibility of the process steps for each device not only complicates the fabrication process, but also decreases the yield. Thus there is a need to provide an improved method of fabricating bipolar and MOS devices on the same semiconductor chip, so that the yield and performance of the bipolar and the MOS devices is optimized.
By now it should be appreciated that it would be advantageous to provide an improved and simplified method of fabricating high performance bipolar transistors that is also compatible with a method of fabricating MOS transistors.
Accordingly, it is an object of the present invention to provide an improved, simple method of fabricating high performance bipolar devices and MOS devices which is easily scalable.
Another object of the present invention is to provide an improved method of fabricating a bipolar device having reduced base and emitter resistances, and reduced collector-base capacitance.
A further object of the present invention is to provide an improved method of fabricating a high performance bipolar device having greater switching speed.
Yet another object of the present invention is to provide an improved method of fabricating a bipolar device with sidewall spacers, a self-aligned emitter-base structure, and minimum emitter to extrinsic base spacing thereby reducing base resistance and allowing for a higher density of integration.
Still a further object of the present invention is to provide an improved method of fabricating bipolar devices that is compatible with a method of fabricating MOS devices.